Ultrathin Hexagonal SnS2 Nanosheets Coupled with Tetragonal CuInS2 Nanosheets as 2D/2D Heterojunction Photocatalysts Toward High Visible-Light Photocatalytic Activity and Stability

A kind of 2D/2D heterojunction photocatalysts was constructed by a facile in situ hydrothermal method that a tetragonal CuInS 2 nanosheets was horizontal loaded in ultrathin hexagonal SnS 2 nanosheets. Contrasted to pure CuInS 2 and SnS 2 nanosheets, the CuInS 2 /SnS 2 nano-heterojunctions revealed a noteworthy improvement photocatalytic activity under visible light irradiation for the degradation of organic dyes, which should be attributed to the narrowest band gap and the efficient charge separation and transfer improving the contact region in heterojunction interface. Especially, with 0.5 wt% addition of CuInS 2 , the heterojunction nanosheets shows a supreme visible-light photocatalytic activity and a superb degradation efficiency which reached 99% in 60 min with the solution of methyl orange. Moreover, CuInS 2 /SnS 2 nano-heterojunctions deliver excellent reusability in five degradation–regeneration cycles. The results indicated that CuInS 2 /SnS 2 has a promising prospect in organic pollutant treatment due to high efficiency and excellent stability. Graphical Abstract